Method of producing color-photographic images and cinematograph films and light-sensitive emulsion therefor



May ll, 1937. B, GASPAR 2,080,041v METHOD OF PRODUCING COLORPHOTOGRAPHIC IMAGES AND CINEMATOGRAPH FILMS AND LIGHT SENSITIVE EMULSIONTHEREFOR Filed March 21, 1955 N 1 5e/a @a5/Joy',

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Patented May 1 1, i937 STATES METHOD oF PRoDUCiNG coLoa-rnoro- GRAPHICIMAGES AND oiNEMA'roGRArn FILMS AND f SION THEREFOR LIGHT-SENSITIVE uEMUL- Bela Gaspar, Brussels, Belgiign Application March 21, 1935, SerialNo. 12,254 In Germany March 29, 1934 vs claims.

This invention relates to a method of producing single-color ormulti-color photographs and cinematograph lms.

It is known to `produce photographic images with the assistance ofmaterials containing the dyestufl', which is necessary for the formationof the image, in the light-sensitive layer. The absorption of thecolored layers is, however, obstructive for numerous purposes in thephotographic art. In particular it is impossible to sensitize the layerssufficiently in respect to the spectral ranges in which the dyestuffsperform absorption.

The subject matter of the invention is a method by which there may beobtained a suihcient amount of dyestuf as required for photographic andmore particularly color-photographic purposesin such a form that thepresence of the dy'estui does not prevent the light from reaching thesensitized particles even in the absorption range of the dyestui.

It has been found that dyestufs in coarsely dispersed form (for example,in the form of'intermittently distributed particles of powder) color theb-inding4 agent merely weakly or practically not at all. The layerscontaining dyestui in coarsely dispersed form are highly transparenteven for light which would be absorbed if the same dyestuifs werepresent in dissolved or finely distributed form. According to theinvention, theV photographic image is produced in good transmittantlayers of. this kind, and after exposure the emulsion layer is fastlydyed by dissolving the coarse grains of coarsely dispersed dyestu withinthe layer, whereupon the layer is rendered highly absorptive. The colorintensity may be predetermined exactly by the amount of coarselydispersed dyestui, dispersed in the emulsion during the manufacture ofthe material. The latent silver image may be developed before or afterthe transformation of the coarsely dispersed dyestuff into finelydistributed dyestui. The dyestui is then locally destroyed proportionalto the metallic silver image.

By way of explaining the invention, reference may be had to the singleligure of the accompanyingv drawing which represents a ow diagramshowing the various steps in the practice of applicants method.

As will be understood from the following description, the sequence ofthe steps in my'improved method'may be changed provided that theunexposed material contains the coarse grained dyestui and that thedyestuff dissolution comes after the exposure.

The dyestuii is introduced into light-sensitive (ci. sis-s) layers, orinto the solutions or emulsions employed for producing the same, incoarsely dispersed form exhibiting little or no absorption. Under theseconditions there will occur merely a weak coloring and a small shadingeffect of the particles. The dye'stu', after the exposure, is thenconverted at a desired point in the treatment of the image from thecoarsely dispersed, non-coloring form into the color-effective form.This is performed either by means of suitable solvents or by chemicalsubstancesv which cause a. diffuse coloring of the layer. It isimmaterial whether these agents transform the dyestuff chemically orconvert it into a colloidal or highly dispersed powerfully absorbingform.

Example-Spirit Fast Red B (Ullmann, Enzyklopdie der Technischen Chemie,2nd ed. vol. 9, page 572) in powder form is admixed with gelatine. Theproportion of powdered dyestu to gelatine must be so chosen that afterpouring on to a support the powdered dyestui is distributedintermittently; i. e., that the gelatine still-possesses a goodtransparency. The quantity of dyestuif should also not be greater thanis necessary for a sui'liciently good diffuse coloring of the layer.obtained during the later process by converting the dyestui into thenely dispersed color-effective form, for example by bathing in adilutedV alcohol solution.

The solution must have a concentration at which on the one hand thegelatine still swells, but at which on the other hand the dyestui isdissolved. With an excess of powdered dyestui the shading effect is tooconsiderable, which is detrimental to the exposure of the layer. Y Forproducing layers whichcontain dyestufl's in coarsely dispersed form,dyestuis are very suitable which are insoluble or difcultly soluble inwater assuming that water-'soluble or saturable binding agents (forexample gelatine) are employed. For binding agents which are insolublein water dyestuis will be employed which are insoluble or difllcultlysoluble in the solvents for the binding agent. t

' The dyestuff is either introduced into the binding agent mechanicallyprior'to pouring, or applied to the surface of the layer either bydusting on or by pouring on to the layer in a suspension, with orwithout binding agents. The dyestuif may also be dissolved in a solvent,which does not cause swelling of the binding agent and upon evaporationleaves the dyestuf as a coarsely distributed sediment.

The dyestu may be introduced into the bind- 'Ihis diffuse coloring isthen gelatine solution by rapid agitation. The dyeing agent' by means ofan auxiliary solvent. For example, a water-insoluble, alcohol-solubledyestui `is dissolved in alcohol, and introduced into stui will beprecipitated in larger or smaller size of grain dependent on the natureof the agitation and the concentration of the dyestuif solution. r v

In this connection it is to be observed that in the gelatine solutionthe alcohol should not reach that concentration at which the grainsv ofdyestuif again dissolve. Alcoholic solutions of QuinolineYellow-spirit-soluble (Schultz Farbstofftabellen 'lth ed. vol. 1, No.917) and the tannates or abietinates of basic dyestuiis, for example ofMethylene Blue (Schultz, loc. cit. No. 1038) Janus Blue (IndoineBlue B,Schultz, locncit. No. 286), Red (Schultz, loc. cit. No.,557) or Yellow(Schultz, loc. cit. No. 292), or of Chrysoidine (Schultz, loc. cit. No.27) are suitable. These solutions are poured into water, the dyestuisalts then being precipitated in ake or granular form. .The waterysuspension oftthese particles of dyestuil is mixed with gelatinesolution. 'I'he solutions-may also be poured directly into the gelatine.The dyestuffs may also be dissolved invwater and precipitated. .Afterthe precipitation the deposit' is ltered and freed from excess ofprecipitating agent by washing, and then mixed with a binding agent withor without a light-sensitive substance. The precipitation may also beperfumed in the presence of the binding agent. If there is a sujcientexcess of the precipitating agent, a coarsely dispersed precipitation ofthe dyestui maybe obtained. In this case the conditions are the same asin the preparation of the emulsion, in which it is possible by varyingthe known factors to obtain coarse-grain or fine-grain deposits in thelayer. In addition to the basic dyestuffs aforesaid acid and substantivedyestuis, such as Anthosine (Schultz, loc. cit. No. 51) li/etanillYellow (Schultz, loc. cit.'No. 169), Naphthylamine Black (Schultz, loc.cit. No. 229) and Diamine Pure Blue `(Schultz, loc. cit. No. 510), arealso suitable.

These are precipitated with salts of the alkaline earths,l magnesium orwith heavy metal salts, such as zinc orA silver salts, oralso with saltsof organic bases, for example aniline or naphthylamine. be precipitatedby the addition of salt.

The precipitation may take place both in water as well as in thepresence of binding agents. The size of grain will depend only on theknown factors. The binding agent solution may be allowed to solidify,and freed from the soluble constituents in the usual fashion by washing.

The most suitable are very dimcultly soluble dyestuffs, which dissolvein 4water only when hot and upon cooling are completely precipitated.These may be employed Without precipitating agents. The dyestui may alsobe allowed to form immediately in the coarse-grain form in solution orin the binding agent fromthe. preliminary stages or components, forexample from 'I'he di'iculty soluble dyestus may also treatment of theimage the dyestufls are converted into a 'condition in which theydevelop their full coloring effect, i. e., diffusely color the layer.For diiuse coloring of the llayer the coarsely dispersed dyestu locatedon the surface of the layer or below the layer may creep into the layerand diifusely color the same.

There are various possibilities of converting the coarsely disperseddyestuff; into the powerfully absorbing, dissolved or' nely distributedform.

.For example, a tannic salt of a basic dyestufi will pass into solutionwith acids. It is advantageous if the acid employed possesses chemicallyagreater alnity for the dyestui than that used for precipitation.Numerous salts of aciol dyestuis pass into solution with diluted alkalisor also with acids. For example, the dyestu passes from the barium saltof chrysophenine or anthosine into solution in 1% sulphuric acid. Inthis case barium sulphate is formed. The barium sulphate is morediiicultly soluble than the dyestuii` salt, i. e., barium has a greater'i'i .l ity towards the sulphate-ion, and accordingly, the dyestui isagain liberated. The coarsely dispersed grains pass into solution eitherin the presence of the acid or upon the subsequent washing, the layerbeing difusely colored. Neutral dyestus insoluble or diilicultly solublein water pass partially into the diiusely coloring soluble form in aWeak acid or also alkaline solution. Very suitable, for example, arethose water-insoluble or diicultly soluble dyestuis such as employed fordyeing acetate silk.

It is also possible to employ vat dyestuis in coarsely dispersed form,and to treat these with an alkaline hydrosulphite solution' in thelayer.'

whereby the layer is difusely colored.

The diuse coloring of the layer may be easily regulated by the durationof the bath or by suitable interruption baths, such as water or likemeans, which act in chemical opposition to the dissolving agents, sothat in case of requirement a bleeding of the dyestui or passage of thedyestui from one layer into the other may be prevented.

The most suitable for this purpose are' solutions of precipitatingagents, which are capable of causing the process of diffusion to be.stopped when a sufficient diiuse coloring of the material has beenattained. It has been found to be oi particular advantage to employthose precipitating agents,` which not only prevent the diusion but alsoimprove the fastness or insolubility of the dyestuff, for example metalsalts, such as' aluminum or copper salts, which form mordants or lakes,or for basic dyestuls solutions of phos- -photungstic or phosphomolybdicacid.

There is employed with advantage upon the conversion of the vcoarselydispersed dyiestuil, which colors the layer only very little or not atall, into the coloring form one of the baths usual in photographicprocesses, the alkaline, acid or solventconcentration of which isadjusted according to the dyestui employed. For example, the conversionof a dispersed dyestu, which reacts in an alkaline agent, into thecoloring form may take place in the developer. If an acid medium isnecessary for this purpose, there will be employed either theinterrupting bath following on the developer, the acid xing bath, or

a dyestuff-destroying bath, for example a solution of thiocarbamidecontaining mineral acid.

The dyestuif may be caused to color the layer diiusely by physicalaction.

Examples.-'1. In a llayer of resin a coarsely 2. On to the surface of alayer there is dusted a fusible dyestufi in powder form which, after theexposure, is caused to color the surface diffusely by fusing.

The production of the dyestuff images inthe layers in accordance withthe invention may` l5 take place in desired fashion according to themethods usual in the photographic and colorphotographic art, preferablyby local destruction of the dyestuff in accordance with earlierprocesses of the applicant. It is possible to produce 2@ with vthedyestuff in the layer for example washout reliefs or mordant or tannedimages, or also to remove the dyestuii' from the tanned points bysolution.

The layers containing coarsely. dispersed dyestuff may be sensitizedwith desired substances,

for example with silver halide, with light-sensitive heavy metal salts,such as those of iron orl mercury, With chromates, or also with organiclight-sensitive substances, such as diazo compounds. The light-sensitivesubstances may either already be added to the emulsion or introducedsubsequently into the nished layer. Themost important use of the layersconsists, however, in the combination with silver halide in one or morelayers, which if desired may be differently sensitized.

The technical advantage of the invention resides in the extensivedecrease or preclusion of the interferlngabsorption (screening eiect) of4G the layers .which contain the coarsely dispersed dyestuis. This isparticularly important in the production of color photographs andcinematograph films. l According to the present invention,

color photographic and cinematographic expoe sures and copies may bemade in direct fashion from colored originals, wherebyv the layers maybe well sensitized directly for the complementary color.

A preferred form of embodiment of the invention resides in the use ofphotographic materials having layers poured one on to the other, theselayers containing diierent dyestus and possessing different spectralsensitivity. In this connection, in addition to the reduced absorptionof the dyestuis, the great lack of diffusion on the part of thesuperimposed layers offers particular advantage. In the same manner itis also possible to produce different dyestuffs and diierentlycolor-sensitized particles of emulsion, which are superimposed orjuxtaposed in screen-like fashion. These are produced by mixing orreemulsifying the differently colored and sensitized particles ofemulsion. 'I'he dyestui. however, may also be provided in coarselydispersed form above or below the light-sensitive layer in screenlikefashion. Further, there may be produced according to the invention notonly colored lightsensitive layers. but also multi-color screens orlayers which are diffusely colored subsequently after the exposure. Thedyestuifs may also be combined with sensitizers and auxiliary lterdyestuis. For this purpose there may be employed iilter dyestuis whichare capable of being both readily washed out as well as destroyed in 75the treatment baths.

It is also possible to combine colorless layers or layers or particlesof layers which are diffusely colored or containdyestuff-formingsubstances.

The coarsely dispersed dyestufis may also be applied above or below thelight-sensitive layer with or without binding agents by dusting on or,as described above, with the assistance of solvents.

The dyestui employed may be selected either' to `be complementary orsimilar to the color sensitivity of the layer or also independentlythereof. It is thereby easily possible to produce master images,`thecolor of which is complementary to the color sensitivity of the coloredcopying layers employed.

An additional advantage of the process according to the invention occursin those cases in which the layer contains dark dyestuifs, e. g. inconnection with documental-or reversal papers or films, which must givedark pictures. In such cases, it would be diiicult to obtain a suiicientexposure if the dyestui is present in the layer in nely dispersed form.If, however, comparatively large dyestuf particles are in the layer,there are suiiicient gaps for the light to penetrate. In a similarmanner gelatine layers for the chromate process can be made withcoarsely dispersed dyestuffs, which are transformed after exposure intoa nely dispersed form.

On the layers according to the invention it is also possible to producesound records, either in colors or also in black-and-White. It wassurprising in this connection that the coarsely dispersed grains ofdyestufi had no adverse effect on the sharpness of the sound copy. Anadvantage resides in the fact that the sound may be copied with thelight ofA the normal soundcopying machines, which is comparatively Weakfor colored layers.

What I claim as new and desire to secure by Letters Patent is:

1. The method of producing photographic dyestui' images which comprisesexposing a light sensitive silver halide emulsion layer, the said layercontaining coarse grains of fast dyestuff coarsely dispersed in anVemulsion which will transmit light raysfor which the coarselydistributed dyestuf possesses absorption properties, fastly dyeing theemulsion layer at a point in the process after exposure by dissolvingthe ,1 coarsely dispersed coarse grains of dyestui withdeveloping vthelatent silver image and destroy-` ing the dyestui locally proportionateto themetallic silver image.

3. The'method of producing photographic dyestui images which comprisesexposing a plu-l rality of superimposed light sensitive silver halideemulsion layers, at least one of the said layers containing a fastdyestui in the form of coarse grains coarsely dispersed in an emul- 4 Yaosaoai .at a point in the process after exposure by dis- 5 solving thecoarsely dispersed dyestui within the layer, developing the latentsilver image and destroying the dyestui locally proportionate to themetallic silver image.

4. The method of producing photographic dye- 10 stuff images whichcomprises exposing a plurality of light sensitive silver halideemulsion.

layers, at least one of the said layers containing a fast dyestut in theform of coarse grains coarsely dispersed in an emulsion which willtransmit and y 25 dispersed coarse grains o'f fast dyestuis in the lightsensitive emulsion prior to exposure and dissolving the grains withinthe layer after exposure.

6. A light sensitive photographic material `comprising a silver halideemulsion layer and 5 coarsely dispersed coarse grains of fast dyestuiwithin the said emulsion, the layer being adapted to 'transmit light ofthe spectral range in which the dyestuff performs maximal absorption. v

7. A light sensitive photographic material comprising a silver halideemulsion layer and coarsely dispersed coarse grains of fast dyestufl.'within the said emulsion,- the layer being adapted to transmit andpredominantly sensitive to light l5 of the spectral range in which thedyestu perf forms maximal absorption.

8. A light sensitive photographic material comprising -a plurality ofsilver halide emulsion layers and coarsely dispersed coarse grains of 20fast dyestuff within at least one of the said emulsion layers, the saidoney layer being adapted to transmit light of the spectral range inwhich the dyestui performs maximal absorption.

BEL GASPAR. 25

